/*
 * Copyright © 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Globalization;

namespace Spring.Objects.Factory.Config;

/// <summary>
/// Immutable placeholder class used for the value of a
/// <see cref="Spring.Objects.PropertyValue"/> object when it's a reference
/// to another object in this factory to be resolved at runtime.
/// </summary>
/// <author>Rod Johnson</author>
/// <author>Rick Evans (.NET)</author>
[Serializable]
public class RuntimeObjectReference
{
    /// <summary>
    /// Creates a new instance of the
    /// <see cref="Spring.Objects.Factory.Config.RuntimeObjectReference"/>
    /// class.
    /// </summary>
    /// <remarks>
    /// <p>
    /// This does <b>not</b> mark this object as being a reference to
    /// another object in any parent factory.
    /// </p>
    /// </remarks>
    /// <param name="objectName">The name of the target object.</param>
    public RuntimeObjectReference(string objectName)
        : this(objectName, false)
    {
    }

    /// <summary>
    /// Creates a new instance of the
    /// <see cref="Spring.Objects.Factory.Config.RuntimeObjectReference"/>
    /// class.
    /// </summary>
    /// <remarks>
    /// <p>
    /// This variant constructor allows a client to specifiy whether or not
    /// this object is a reference to another object in a parent factory.
    /// </p>
    /// </remarks>
    /// <param name="objectName">The name of the target object.</param>
    /// <param name="isToParent">
    /// Whether this object is an explicit reference to an object in a
    /// parent factory.
    /// </param>
    public RuntimeObjectReference(string objectName, bool isToParent)
    {
        _objectName = objectName;
        _isToParent = isToParent;
    }

    /// <summary>
    /// Return the target object name.
    /// </summary>
    public string ObjectName
    {
        get { return _objectName; }
    }

    /// <summary>
    /// Is this is an explicit reference to an object in the parent
    /// factory?
    /// </summary>
    /// <value>
    /// <see langword="true"/> if this is an explicit reference to an
    /// object in the parent factory.
    /// </value>
    public bool IsToParent
    {
        get { return _isToParent; }
    }

    /// <summary>
    /// Returns a string representation of this instance.
    /// </summary>
    /// <returns>A string representation of this instance.</returns>
    public override string ToString()
    {
        return string.Format(
            CultureInfo.InvariantCulture, "<{0}>", ObjectName);
    }

    private string _objectName;

    private bool _isToParent;

    /// <summary>
    /// Determines whether the specified RuntimeObjectReference is equal to the current RuntimeObjectReference.
    /// </summary>
    /// <returns>true if the specified RuntimeObjectReference is equal to the current RuntimeObjectReference; otherwise, false.</returns>
    protected bool Equals(RuntimeObjectReference other)
    {
        return string.Equals(_objectName, other._objectName) && _isToParent.Equals(other._isToParent);
    }

    /// <summary>
    /// Determines whether the specified System.Object is equal to the current RuntimeObjectReference.
    /// </summary>
    /// <returns>true if the specified RuntimeObjectReference is equal to the current RuntimeObjectReference; otherwise, false.</returns>
    public override bool Equals(object obj)
    {
        if (ReferenceEquals(null, obj)) return false;
        if (ReferenceEquals(this, obj)) return true;
        if (obj.GetType() != this.GetType()) return false;
        return Equals((RuntimeObjectReference) obj);
    }

    /// <summary>
    /// Serves as a hash function for RuntimeObjectReference.
    /// </summary>
    /// <returns>A hash code for the currentRuntimeObjectReference.</returns>
    public override int GetHashCode()
    {
        unchecked
        {
            return (_objectName.GetHashCode() * 397) ^ _isToParent.GetHashCode();
        }
    }
}
